Le tridi 13 frimaire, an CCXXIII, anshul.ffm...@gmail.com a écrit : > Subject: Re: [FFmpeg-devel] [PATCH 2/2] Adding closed caption decoder
Very good news!
> I did implement lots of other thing, with respect to older patch.
> like multi screen and rollup feature.
>
> This implementation is working well with srt output format.
> As of now ffplay is not able to show the decoded frames on screen.
> I dont know why?
As far as I know, ffplay can only handle bitmap subtitles, not text
subtitles.
I do not have time to check right now: can you tell if you changed something
in the first patch or if it is mine unchanged?
Just a quick few words for the rest:
> May be someone look at output and help, that what is missing.
>
> libavcodec/Makefile | 1 +
> libavcodec/allcodecs.c | 1 +
> libavcodec/ccaption_dec.c | 376
> ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 378 insertions(+)
> create mode 100644 libavcodec/ccaption_dec.c
>
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index fa0f53d..bbc516d 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -173,6 +173,7 @@ OBJS-$(CONFIG_BRENDER_PIX_DECODER) += brenderpix.o
> OBJS-$(CONFIG_C93_DECODER) += c93.o
> OBJS-$(CONFIG_CAVS_DECODER) += cavs.o cavsdec.o cavsdsp.o \
> cavsdata.o mpeg12data.o
> +OBJS-$(CONFIG_CCAPTION_DECODER) += ccaption_dec.o
> OBJS-$(CONFIG_CDGRAPHICS_DECODER) += cdgraphics.o
> OBJS-$(CONFIG_CDXL_DECODER) += cdxl.o
> OBJS-$(CONFIG_CINEPAK_DECODER) += cinepak.o
> diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
> index 0d39d33..8c07388 100644
> --- a/libavcodec/allcodecs.c
> +++ b/libavcodec/allcodecs.c
> @@ -480,6 +480,7 @@ void avcodec_register_all(void)
> /* subtitles */
> REGISTER_ENCDEC (SSA, ssa);
> REGISTER_ENCDEC (ASS, ass);
> + REGISTER_DECODER(CCAPTION, ccaption);
> REGISTER_ENCDEC (DVBSUB, dvbsub);
> REGISTER_ENCDEC (DVDSUB, dvdsub);
> REGISTER_DECODER(JACOSUB, jacosub);
> diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c
> new file mode 100644
> index 0000000..57443e4
> --- /dev/null
> +++ b/libavcodec/ccaption_dec.c
> @@ -0,0 +1,376 @@
> +/*
> + * Closed Caption Decoding
> + * Copyright (c) 2014 Anshul Maheshwari
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
> USA
> + */
> +
> +#include "avcodec.h"
> +#include "libavcodec/ass.h"
Looks suspicious. Just "ass.h" maybe?
> +
> +#define SCREEN_ROWS 15
> +#define SCREEN_COLUMNS 32
> +
> +#define SET_FLAG(var, val) ( var |= ( 1 << (val) ) )
> +#define UNSET_FLAG(var, val) ( var &= ~( 1 << (val)) )
> +#define CHECK_FLAG(var, val) ( (var) & (1 << (val) ) )
> +
> +enum cc_mode {
> + CCMODE_POPON,
> + CCMODE_PAINTON,
> + CCMODE_ROLLUP_2,
> + CCMODE_ROLLUP_3,
> + CCMODE_ROLLUP_4,
> + CCMODE_TEXT,
> +};
> +typedef struct {
> + int row;
> + int column;
> +} cursor_t;
Names ending in _t are reserved by the C standard.
(And this one specifically looks not really useful: you could just use two
fields cursor_row and cursor_col.)
> +
> +// buffer for CC
> +typedef struct {
> + uint8_t characters[SCREEN_ROWS][SCREEN_COLUMNS+1];
> + /*
> + * row used flag will be 0 when none in use other wise it will have its
> + * corrosponding bit high.
> + * for setting row 1 use row | (1 >> 1)
> + * for setting row 15 use row | (1 >> 15)
> + */
> + int16_t row_used;
> +} screen_t;
Ditto.
> +
> +
> +typedef struct CCaptionSubContext {
> + int parity_table[256];
> + int row_cnt;
> + screen_t screen[2];
> + int active_screen;
> + cursor_t cursor;
> + char *buffer;
> + int index;
> + int data_len;
> + int buf_len;
Maybe you could use the AVBPrint API.
> + /* erase display memory */
> + int edm;
> + int rollup;
> + enum cc_mode mode;
> + int64_t start_time;
> + /* visible screen time */
> + int64_t startv_time;
> + int64_t end_time;
> + char prev_cmd[2];
> +}CCaptionSubContext;
> +
> +static unsigned int av_always_inline is_oddparity1p7(unsigned int val)
> +{
> +//#if defined(__x86_64__) || defined(_M_X64) || defined(__i386) ||
> defined(_M_IX86)
> +#if 0
> + asm goto (
> + "and $0x7F, %0\n\t"
> + "jnp %l1 \/n\t"
> + :/* no output */
> + :"r"(val)
> + :"cc"
> + :odd
> + );
> + val = !(val&0x8);
> +odd:
> + val = !!(val&0x80);
> +#else
Looks only used 128 times at codec init: I suggest to just remove it.
> + int ones = 0;
> + int i = 0;
> +
> + for (i = 0; i < 7; i++) {
> + if (val & (1 << i))
> + ones++;
> + }
> + val = ones & 1;
> +#endif
> + return val;
> +}
> +
> +static void build_parity_table(int *parity_table)
> +{
> + unsigned int byte;
> + int parity_v;
> + for (byte = 0; byte <= 127; byte++) {
> + parity_v = is_oddparity1p7(byte);
> + parity_table[byte] = parity_v;
> + parity_table[byte | 0x80] = !parity_v;
> + }
> +}
> +
> +static av_cold int init_decoder(AVCodecContext *avctx)
> +{
> +
> + CCaptionSubContext *ctx = avctx->priv_data;
> +
> + build_parity_table(ctx->parity_table);
> + ctx->row_cnt = 0;
> + ctx->buf_len = 512;
> + ctx->buffer = av_realloc(NULL, ctx->buf_len);
Please do not forget to check memory allocations. AVBPrint will mostly take
care of it for you.
> + *ctx->buffer = '\0';
> + ctx->index = 0;
> + ctx->edm = 0;
> + /* taking by default roll up to 2 */
> + ctx->rollup = 2;
> + ctx->data_len = 0;
> + /* set active screen as 0 */
> + ctx->active_screen = 0;
> + memset(ctx->prev_cmd,0,2);
> + ff_ass_subtitle_header_default(avctx);
> + return 0;
> +}
> +
> +static av_cold int close_decoder(AVCodecContext *avctx)
> +{
> + CCaptionSubContext *ctx = avctx->priv_data;
> + av_free(ctx->buffer);
> + return 0;
> +}
> +
> +/**
> + * This function after validating parity bit, also remove it from data pair.
> + */
> +static int validate_cc_data_pair (unsigned char *cc_data_pair, int
> *parity_table)
> +{
> + unsigned char cc_valid = (*cc_data_pair & 4) >>2;
> + unsigned char cc_type = *cc_data_pair & 3;
> +
> + if (!cc_valid)
> + return -1;
> +
> + // if EIA-608 data then verify parity.
> + if (cc_type==0 || cc_type==1) {
> + if (!parity_table[cc_data_pair[2]]) {
> + // If the second byte doesn't pass parity, ignore pair
> + return -1;
> + }
> + if (!parity_table[cc_data_pair[1]]) {
> + // The first byte doesn't pass parity, we replace it with a solid
> blank
> + // and process the pair.
> + cc_data_pair[1]=0x7F;
> + }
> + }
> +
> + //Skip non-data
> + if( (cc_data_pair[0] == 0xFA || cc_data_pair[0] == 0xFC ||
> cc_data_pair[0] == 0xFD )
> + && (cc_data_pair[1] & 0x7F) == 0 && (cc_data_pair[2] & 0x7F) == 0)
> + return -1;
> +
> + //skip 708 data
> + if(cc_type == 3 || cc_type == 2 )
> + return -1;
> +
> + /* remove parity bit */
> + cc_data_pair[1] &= 0x7F;
> + cc_data_pair[2] &= 0x7F;
> +
> +
> + return 0;
> +
> +}
> +static void handle_pac( CCaptionSubContext *ctx, uint8_t hi, uint8_t lo )
> +{
> + static const int row_map[] = {
> + 11, -1, 1, 2, 3, 4, 12, 13, 14, 15, 5, 6, 7, 8, 9, 10
> + };
> + const int index = ( (hi<<1) & 0x0e) | ( (lo>>5) & 0x01 );
> +
> + if( row_map[index] <= 0 )
> + return;
> +
> + ctx->cursor.row = row_map[index] - 1;
> + ctx->cursor.column = 0;
> +
> +}
> +
> +/**
> + * @param pts it is required to set end time
> + */
> +static void av_always_inline handle_edm(CCaptionSubContext *ctx,int64_t pts)
Is inlining really that important?
> +{
> + int i,index = 0;
> + screen_t *screen = ctx->screen + ctx->active_screen;
> +
> + ctx->start_time = ctx->startv_time;
> + for( i = 0; screen->row_used && i < SCREEN_ROWS; i++)
> + {
> + if(CHECK_FLAG(screen->row_used,i)) {
> + index += av_strlcpy(ctx->buffer + index, screen->characters[i],
> ctx->buf_len);
> + if (index > ctx->buf_len) {
> + index = ctx->buf_len;
> + ctx->buf_len *= 2;
> + ctx->buffer = av_realloc(ctx->buffer, ctx->buf_len);
> + index += av_strlcpy(ctx->buffer + index,
> screen->characters[i], ctx->buf_len);
> + }
> + index += av_strlcpy(ctx->buffer + index, "\\N", ctx->buf_len);
> + UNSET_FLAG(screen->row_used, i);
> + }
> + }
> + ctx->startv_time = pts;
> + ctx->edm = 1;
> + ctx->data_len = index;
> + ctx->end_time = pts;
> +}
> +static void handle_eoc(CCaptionSubContext *ctx, int64_t pts)
> +{
> + ctx->active_screen = !ctx->active_screen;
> + ctx->startv_time = pts;
> +}
> +static screen_t *get_writing_screen(CCaptionSubContext *ctx)
> +{
> + switch (ctx->mode) {
> + case CCMODE_POPON:
> + // use Inactive screen
> + return ctx->screen + !ctx->active_screen;
> + case CCMODE_PAINTON:
> + case CCMODE_ROLLUP_2:
> + case CCMODE_ROLLUP_3:
> + case CCMODE_ROLLUP_4:
> + case CCMODE_TEXT:
> + // use active screen
> + return ctx->screen + !ctx->active_screen;
> + }
> + /* It was never an option */
> + return NULL;
> +}
> +static void handle_char(CCaptionSubContext *ctx, char hi, char lo, int64_t
> pts)
> +{
> + screen_t *screen = get_writing_screen(ctx);
> + char *row = screen->characters[ctx->cursor.row] + ctx->cursor.column;
> +
> + SET_FLAG(screen->row_used,ctx->cursor.row);
> +
> + *row++ = hi;
> + ctx->cursor.column++;
> + if(lo) {
> + *row++ = lo;
> + ctx->cursor.column++;
> + }
> + *row = 0;
> + /* reset prev command since character can repeat */
> + ctx->prev_cmd[0] = 0;
> + ctx->prev_cmd[1] = 0;
> +}
> +static int process_cc608(CCaptionSubContext *ctx, int64_t pts, unsigned char
> hi, unsigned char lo)
> +{
> +
> +#define COR3(var, with1, with2, with3) ( (var) == (with1) || (var) ==
> (with2) || (var) == (with3) )
> + if ( hi == ctx->prev_cmd[0] && lo == ctx->prev_cmd[1]) {
> + /* ignore redundant command */
> + } else if ( (hi == 0x10 && (lo >= 0x40 || lo <= 0x5f)) ||
> + ( (hi >= 0x11 && hi <= 0x17) && (lo >= 0x40 && lo <= 0x7f) ) )
> {
> + handle_pac(ctx, hi, lo);
> + } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x20 ) {
> + /* resume caption loading */
> + ctx->mode = CCMODE_POPON;
> + } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x25 ) {
> + ctx->rollup = 2;
> + } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x26 ) {
> + ctx->rollup = 3;
> + } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x27 ) {
> + ctx->rollup = 4;
> + } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x29 ) {
> + /* resume direct captioning */
> + ctx->mode = CCMODE_PAINTON;
> + } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2C ) {
> + /* erase display memory */
> + handle_edm(ctx, pts);
> + } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2D ) {
> + /* carriage return */
> + if(ctx->buf_len < ctx->index + 3 ) {
> + ctx->buf_len *= 2;
> + ctx->buffer = av_realloc(ctx->buffer, ctx->buf_len);
> + }
> + ctx->row_cnt++;
> + if(ctx->row_cnt == ctx->rollup) {
> + ctx->row_cnt = 0;
> + ctx->buffer[ctx->index ] = 0;
> + handle_edm(ctx, pts);
> + }
> + /* If there is no data or end of data then no point using cr */
> + if(ctx->index) {
> + ctx->buffer[ctx->index] = '\\';
> + ctx->index++;
> + ctx->buffer[ctx->index] = 'N';
> + ctx->index++;
> + }
> + } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2F ) {
> + /* end of caption */
> + handle_eoc(ctx, pts);
> + } else if (hi>=0x20) {
> + /* Standard characters (always in pairs) */
> + handle_char(ctx, hi, lo, pts);
> + } else {
> + /* Ignoring all other non data code */
> + }
> +
> + /* set prev command */
> + ctx->prev_cmd[0] = hi;
> + ctx->prev_cmd[1] = lo;
> +
> +#undef COR3
> + return 0;
> +
> +}
> +static int decode(AVCodecContext *avctx,
> + void *data, int *got_sub,
> + AVPacket *avpkt) {
Strange indentation.
> + CCaptionSubContext *ctx = avctx->priv_data;
> + AVSubtitle *sub = data;
> + unsigned char *bptr = avpkt->data;
> + int len = avpkt->size;
> + int ret = 0;
> + int i;
> +
> + for (i = 0; i < len; i += 3) {
> + unsigned char cc_type = *(bptr + i) & 3;
> + if (validate_cc_data_pair( bptr + i, ctx->parity_table ) )
> + continue;
> + /* ignoring data field 1 */
> + if(cc_type == 1)
> + continue;
> + else
> + process_cc608(ctx, avpkt->pts, *(bptr + i + 1), *(bptr + i + 2));
> + }
> + if(ctx->edm && *ctx->buffer)
> + {
> + int start_time = av_rescale_q(ctx->start_time, avctx->time_base,
> (AVRational){ 1, 100 });
> + int end_time = av_rescale_q(ctx->end_time, avctx->time_base,
> (AVRational){ 1, 100 });
> + ret = ff_ass_add_rect(sub, ctx->buffer, start_time, end_time -
> start_time , 0);
> + if (ret < 0)
> + return ret;
> + sub->pts = av_rescale_q(ctx->start_time, avctx->time_base,
> AV_TIME_BASE_Q);
> + ctx->edm = 0;
> + }
> +
> + *got_sub = sub->num_rects > 0;
> + return 0;
> +}
> +
> +AVCodec ff_ccaption_decoder = {
> + .name = "cc_dec",
> + .long_name = NULL_IF_CONFIG_SMALL("Closed Caption Decoder"),
> + .type = AVMEDIA_TYPE_SUBTITLE,
> + .id = AV_CODEC_ID_EIA_608,
> + .priv_data_size = sizeof(CCaptionSubContext),
> + .init = init_decoder,
> + .close = close_decoder,
> + .decode = decode,
> +};
Regards,
--
Nicolas George
signature.asc
Description: Digital signature
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
